Question 3.
a) Describe the structure of the immunoglobulin molecule and the functions of the different structural domains.
(12 minutes)
b) How is antibody diversity generated?
(3 minutes)

Question 2
Although primary immunodeficiency disorders are rare, they help us to understand the importance of various components of the immune system in host defences.
Outline four broad categories of primary immunodeficiency.
For each, write brief notes on important function of the deficient component and relate this to the type of micro-organisms causing infection in the immune-deficient individual.

Question 5:
Untreated patients with HIV may present with severe infection as the first manifestation of their disease.

Question 6:
Briefly outline the importance of Antibodies. (6minutes)

Question 5.
Infants with primary (congenital) T cell deficiency present with severe infection and failure to thrive.

a) Briefly describe important T cell functions which are lacking in such patients.
(8 marks)
b) Give examples of the types of micro-organisms to which such patients are particularly prone.
(4 marks)

Question 3

Interaction with a pathogen induces a number of innate and acquired immune processes. Briefly outline the host responses that are induced by a bacterium invading the body from the respiratory tract.
(23 marks)


Question 1.

Individuals with humoral (antibody) deficiency often present with bacterial infections of the respiratory tract.
Individuals with T cell deficiency have a tendency to develop severe viral, fungal or TB infection as well as bacterial infection.
Using your knowledge of antibody functions and T cell functions, explain why these infection profiles differ.
(10 marks)
Question 1.
(a) Compare and contrast the structure of Immunoglobulin M and Immunoglobulin G.
(5 marks)
(b) Write notes on the function of IgG antibodies and their role in specific immune defences.
(6 marks)

Question 5.
A 6 week old infant presents with failure to thrive, oral candidiasis, diarrhoea and recurrent pneumonia. Investigation reveals a very low lymphocyte count. HIV testing is negative.


Question 1:
Patients infected with human immune-deficiency virus (HIV) may present with opportunistic infections as the first manifestation of HIV AIDS.

Question 6.
Briefly discuss the following:
a) What is a granuloma? Outline the cell types involved and their function in the formation of the granuloma.
(6 marks)
b) Give a cause for each of the following:

Explain what is meant by these terms.
(6 marks)